node.js – can’t run the web app through node server.js

can’t run server.js at localhost 3000 with the code:

const express = require('express')
const app = express()

app.set('view engine', ejs)
app.use(express,static(public))

app.listen(3000)

Getting the error as:

$ node server.js

ReferenceError: ejs is not defined
    at Object.<anonymous> (C:\Users\Hayyan\Desktop\PAYMENTS W NODE.JS AND STRIPE\server.js:4:24)
    at Module._compile (node:internal/modules/cjs/loader:1105:14)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1159:10)
    at Module.load (node:internal/modules/cjs/loader:981:32)
    at Function.Module._load (node:internal/modules/cjs/loader:822:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:77:12)
    at node:internal/main/run_main_module:17:47